Pipe sling



' Feb. 4, 1969 E, SUTTON I 3,425,737

PIPE SLING Filed Aug. 28, 1967 Jimmy 5 Sufi 0n INVENTOR.

BYWM

ATTORNEY United States Patent Olhce 3,425,737 Patented Feb. 4, 1969 6 Claims ABSTRACT OF THE DISCLOSURE For use in lifting pipes and other elongate objects, pipe sling apparatus preferably engaged by an overhead apparatus providing a lifting force to a connector means, an elongate means of generally flexible and planar construction adapted to extend around a pipe and having two ends, at least one of which is releasably connected to the overhead lifting apparatus wherein said elongate means is fabricated of a plurality of preferably Woven straps adapted to sustain a substantial load, a cloth wrapping about the plurality of straps and stitched thereto, and impregnated to form an abrasion-resistant surface to protect the elongate means from damage.

Summary of problem and invention The construction of a large diameter pipe line requires distribution and handling of the pipe sections. Routinely, they are unloaded from a truck or other vehicle maneuvered into a parallel location adjacent the excavation or ditch, hoisted above the terrain and into the excavation and joined to the pipe previously positioned in the ditch. While construction techniques may vary from the foregoing, it is recognized, of necessity, that the pipe must be handled in generally difficult circumstances. It is with a view of pipe handling and its many related problems that the present invention is summarized as providing an elongate means including a connector means which is adapted to be placed about a pipe for lifting by overhead apparatus. More particularly, the present invention is summarized as including a plurality of preferably woven elongate members which are quite strong individually and which are encased in a fabric wrapping which forms an essentially planar pipe sling which is impregnated to form an abrasion resistance means.

The present invention is more readily understood from a consideration of the included drawing wherein:

FIG. 1 is a perspective view of the present invention in use in lifting a pipe; and,

FIG. 2 is an isometric view of a substantial portion of the pipe sling with the fabric cover broken away to disclose additional details of construction, it being apprecialted that the pipe sling includes two ends preferably of similar or identical construction.

In the drawing, attention is directed first to FIG. 1 of the drawing which illustrates a pipe 10 lifted by the sling of the present invention identified by the numeral 12. A hoist cable 14 is connected to a head iron 16 which then engages the pipe sling 12 of the present invention for lifting the pipe 10. Thus, it will be appreciated that the structure shown in FIG. 1 permits the overhead lifting apparatus 14 to be positioned above the pipe 10 and the pipe sling 12 passed under the pipe and engaged with the head iron 16 for lifting the pipe 10.

Attention is directed to FIG. 2 of the drawing which will be described in detail prior to returning to FIG. 1. The pipe sling of the present invention is indicated by the numeral 12 in FIG. 2. It will be appreciated that the structure is substantially elongate with a portion thereof omitted since both ends of the pipe sling are identical, and since the central portions vary only in length and are fabricated in the same manner'along the length. With this point in a l y mind, attention is directed to an end iron 18 which extends substantially transverse to the loading acting on the pipe sling. The end iron 18 is a generally rectangular metal plate of substantial strength. A number of holes 20 are adapted to be engaged by lifting means of the head iron 16 as will be described. Additionally, substantially elongate slots 22 are formed across the length of the end iron 18 near one edge for receiving a plurality of load bearing members as will be described. The slots 22 are preferably slightly wider than the means passed therethrough for ease of interconnection and need have only sufficient width to pertmit access during assembly. The number of slots 22 is subject to variation as are the spacing and actual size. At any event, it will be appreciated that one slot 22 is provided for each of the elongate members placed therein and their spacing is such as to not cause excessive stress concentrations in the end iron means 18.

Note should also be taken of the number of holes 20 formed in the end iron 18 for engaging with the head iron 16. The number of holes is likewise subject to variation and need only to transfer the weight of the pipe 10 to the end iron without weakening between adjacent holes.

The narrow face or dimension of the end iron 18 is curved or rounded at 24.

The pipe sling 12 of the present invention is adapted to be substantially long in the completed form. For instance, widths of 42 inches are not uncommon, and lengths substantially over ten feet are occasionally used to lift pipe perhaps three feet or greater in diameter. For purposes of discussion and as an illustrative size only, the pipe sling 12 is presumed to be ten feet in length, in describing the construction of one embodiment hereof. For a length of perhaps ten feet, a plurality (between four and twenty) of nylon-like belts (webbing or Woven construction) are placed parallel to one another and looped through the openings 22 in the end iron 18. The second end iron (not shown) is spaced the appropriate distance from the first, and one selected nylon-like Webbing belt 28 is threaded through each opening 22 in the end irons 18, with each belt 28 passing through like openings at each end. It will be understood that the two ends of each nylon webbing belt 28 are brought together at some point between the end iron pieces 18 and are sewed together. it is not particularly critical that the spliced ends of the belt 28 be located at soime mid-point, although it is preferable to not position the splice of the belt ends at the openings 22 in the end irons 18.

Attention is directed to the loop 28a shown in FIG. 2 wherein it is illustrated that the webbing 28 is looped through the selected opening 22 in the end iron and is doubled back on itself for the length of the pipe sling.

As noted above, the number of webbing belts 28 included across the width of the sling is subject to some variation, although they should be in sufiicient number to sustain the load placed on the sling 12. At any event, the webbing belts 28 are located substantially fully across the Width of the sling 12 and are positioned at both edges of the sling 12. Then, a preferably woven cloth cover including a lower planar portion 30 and an upper planar portion 32 i placed about the pipe sling including the end irons 18 and the webbing belts 28. The curved ends 24 of the end irons mayprotrude from the encasing cloth positioned about the webbing belts. It is not necessary to fully enclose the end irons; however, it is preferable to fully Wrap the Woven cloth cover around the belts 28 and most edges of the end irons 18 to prevent sharp edges from scratching the pipe 10. Preferably, the cloth wraps just around the edgemost Webbing belts of the sling to define its optimum width and extends fully over the end irons to define the optimum length. The cloth is joined to the belts 28 wherein the cover is sewed by the seam of stitches 36 to the various belts. Internal placement of the belts 28 with respect to the cover is of significance. It is desirable that the belts 28 are spaced evenly along the length of the pipe sling 12 to maintain uniform strength, thickness and load distribution and to prevent bunching or limpiness of the completed structure. Moreover, in the preferred method of assembly, one side of the encasing cloth sack (perhaps the lower cover 30) is first positioned adjacent the webbing belts and is sewed thereto to position the various elongate elements. Thereafter, the upper cover 32 is placed on the webbing belts and the stitches 36 indicate that the upper cover is also sewed to the partially assembled structural elements to form the permanent structure. As a further alternative, the cloth encasement may be of sock construction or may be for-med of a single elongate cloth which is wrapped about the device.

It should be noted that the cloth cover extends over the end iron 18 and a plurality of openings 32a are formed in the cover itself to permit access to the openings 20 in each end iron. On the other hand, the slots 22 (of assistance in stringing the webbing 28) are covered and no other openings are found in the completed pipe sling.

Note should be taken of the materials for fabrication of the present invention. Preferably, the webbing belts 28 are of nylon, which is quite strong and relatively inexpensive. In addition, nylon provides a woven belt which is quite flexible and is endowed with other physical characteristics desirable for a pipe sling. The width, thickness and even thread size is left to choice and depends on a number of circumstances of useage. Of further interest is the fact that the cloth cover is best a continuous member which fully surrounds the pipe sling. It may have a seam or seams which are best perhaps located at either edge, or it may be a continuous sock-like member open only at the ends with the seams formed at the extremes of the end irons 18. The location of the sea-ms is of no particular consequence so long as they are substantially joined to provide the desired encasing for resistance of abrasion as will be discussed.

Cotton has been found to be very suitable material for the cloth cover, although other cloth materials may be used. Preferably, the cloth cover is impregnated with polyurethane to yield a degree of resilience and abrasion resistive characteristics to the completed pipe sling 12. It will be appreciated that some pipe is uncoated and is quite rough on the exterior; further, the circumstances of use require the pipe sling to be snaked under a pipe on abrasive ground surfaces such that the pipe sling not availing itself of abrasion resistive means is badly frayed by the surfaces. The use of polyurethane to impregnate the cloth cover substantially increases the life of the pipe sling. As a matter of fact, the abrasion encountered by the pipe sling, absent the cloth cover and the chemical impregnation, is sufficient to destroy the nylon webbing belts in short order and to generally bar the use of the pipe sling in actual field conditions. However, in the circumstances of the present invention, the life of the pipe sling is not merely enhanced, but is substantially multiplied by the use of the chemically impregnated cover which resists and absorbs the abrasive effects of the circumstances of use of the pipe sling Note should be taken of the cloth wrapping. One weight of cloth is about one-eighth inch thick, and has three layers of cloth. The product is similar to industrial cloth belting. The nylon webbing is best selected from military specified inventories and is preferably one and three- -fourths inches wide. Since the cotton cloth does not stretch, a stretchable cloth can be adapted in lieu of the cotton cover.

While the foregoing describes the nature of the present invention, it is described hereinbelow in operation to convey further understanding of the pipe sling. In routine operations, the overhead lifting apparatus 14 is positioned above the pipe 10 with the pipe 10 resting on the ground, skids, or some other surface. The head iron 16 is carried on the hook and the cable is positioned above a central point of the pipe 10. The pipe sling 12 of the present invention is engaged with one side of the head iron 16. As shown in the drawings, the head iron includes a number of hooks, perhaps five, on opposite sides. The hooks on one side of the head iron 16 are engaged with the openings 20 in the end iron 18 at one end of the pipe sling 12. It is of no particular consequence which end is first engaged to the head iron, and which faces of the sling is presented to the pipe in contact with the pipe. The pipe sling 12 is then snaked under the pipe 10 by appropriate means. For instance, a small rope can be used to pull the free end of the pipe sling 12 under the pipe 10. Because of the relative thinness of the pipe sling, no particular problem with preliminary lifting of the pipe 10 is encountered. Moreover, it is possible to position the pipe 10 over the sling 12 when the pipe 10 is removed from the vehicle and placed on the ground. At any event, the pipe sling 12 is placed beneath the pipe 10 to permit lifting of the pipe in the below described manner.

After the pipe 10 is positioned over the central portions of the sling 12, and with one end engaged with the head iron, the head iron is lowered sufficiently to permit the free end of the pipe sling to be hooked to the head iron. Then, the lifting apparatus raises the head iron above the pipe 10 and the pipe sling is pulled taught in the manner illustrated in FIG. 1. At this juncture, the apparatus is in position to lift the pipe 10 carried by the apparatus.

it is possible to lift upwards of two hundred tons of pipe utilizing the device of the present invention. Moreover, the abrasive surfaces, even with a pipe 10 which Weighs as much as two hundred tons, do not damage or wear the pipe sling 12 since the cover surrounding the load bearing members within the pipe sling protects them from abrasion, rough handling, and the like. Moreover, the pipe sling 12 is adapted to resist abrasion caused by the surface of the pipe or the surface of the ground, the ditch into which the pipe is placed, or other environmental conditions.

Note should be taken of various sizes of the present invention. For one large sling useful in lifting pipe of perhaps forty-two inches in diameter, and weighing several tons per section, the device of the present invention has a belt width of up to forty-eight inches with the belt length of approximately fifteen feet. The total weight of the large pipe sling is less than two hundred pounds, permitting one man to effect connection to the overhead lifting apparatus. In further particular, the weight can be substantially less for smaller models. It will be appreciated that even with the maximum size, the pipe sling 12 of the present invention is routinely handled by one man. Moreover, the pipe sling is connected to the head iron 16 by one man, since the sling itself is quite flexible and can be easily maneuvered into position for engaging the hooks of the head iron 16.

What is claimed is:

1. A pipe sling comprising:

(a) first and second load-supporting members having transverse openings in portions thereof;

(b) a plurality of paralleled belts extending between said load-supporting members and respectively looped through said transverse openings for transferring loads form said belts to said load-supporting members;

(0) abrasion-resistant means encasing said belts and at least said portions of said load-supporting members in which said transverse openings are located; and,

(d) means on said load-supporting members adapted for releasable connection to pipe-handling apparatus.

2. The pipe sling of claim 1 wherein said connecting means on each of said load-supporting members are comprised of at least one opening in each of said load-supporting members adapted to receive a portion of such pipehandling apparatus.

3. The pipe sling of claim 2 wherein said abrasionresistant means include a fabric sleeve covering said belts and said load-supporting members and having openings therein coinciding with said one opening in each of said load-supporting members.

4. The pipe sling of claim 3 wherein said fabric sleeve is impregnated with a chemical for imparting added resiliency and abrasion-resistance thereto.

5. The pipe sling of claim 3 wherein said fabric sleeve is impregnated with ipolyurethane for imparting added resiliency and abrasion-resistance thereto.

6. The pipe sling of claim 1 wherein said abrasionresistant means includes a fabric sleeve covering the flat 6/1952 Knudsen 29474 12/ 1966 Norton 294-74 FOREIGN PATENTS 1,050,789 12/1966 Great Britain.

EVON C. BLUNK, Primary Examiner.

ROBERT D. GUIOD, Assistant Examiner. 

